4-AA LED Bicycle Lights

There is a well-populated class of bicycle headlights that use 4-AA
batteries. This is a very popular category of lighting for commuting
and long-distance cycling.

AA batteries are convenient to carry and easy to find at many
stores. In this class of lights, the battery compartment tends to
dictate the overall shape and size of the light. The choice of 4-AAs
results in convenient all-in-one packaging.

I've decided to compare four lights of this type (that I own) under
reasonably controlled conditions. As stated above, weight-wise and
overall size-wise, they're all about the same.

[For the record, I own many more bicycle lights of different types and
cost levels, including a 10W HID and quite a variety of halogen and
LED lights of different wattages. However, none of the other lights I
own work on 4-AAs.]

From left to right:

Di Notte 5W LED light. My newest purchase for nearfield use
during commuting.

Cateye HL-500II Micro Halogen (2.4W). I own about 7 of
these at last count.
Used mostly for brevets in overvolted mode with Energizer
Lithium AAs.

Cateye EL500 1W LED light. My previous commute mainstay.

Brand new Cateye EL530 1W LED light. Successor to the
EL500. Supposed to be much better.

Here is the test scene:

I positioned three objects of interest:

A red exercise ball at 64 ft (about 2.2 seconds away at 20 mph).

A white floor lamp at 40 ft (about 1.5 seconds away at 20 mph).

A white water bottle at 26 ft (just under 1 second away).

I would characterize the two closer objects as being "nearfield"
in the sense that we react relatively instinctively and
immediately to them in terms of steering input.

The furthest object (and beyond) I would say are "distant" in
the sense that we can recognize and plan for those objects but
we do not need to process them immediately.

So how do they compare? Beam patterns are shown below.

[Link to dpreview.com elements here. Adjust your monitor. You should be able to distinguish between A, B and C, and also X, Y and Z.]

[To see a larger image, click on a picture.]

From left to right:

The scene as illuminated by camera flash only. Overexposed in postprocessing. (Duplicate of above.)

Cateye HL-500II Micro Halogen. Overvolted. Lithium AAs.

Cateye EL500 1W LED light. Lithium AAs.

DiNotte 5W LED light. NiMh AAs.

DiNotte 5W LED light. Lithium AAs. Since the DiNotte is
regulated, this is just a check.

Cateye EL530 1W LED light. Lithium AAs.

Notes:

All pictures were taken under the same conditions: i.e. same
ambient lighting and same camera setting.

An Olympus 720SW point-and-shoot mounted on a tripod was used for
this series. Except for the scene picture, each one was exposed at
shutter speed: 0.5s, F3.5, and 250 ISO.

The exact same set of 4 Energizer Lithium AAs were used for each
shot unless otherwise noted.

The lights have substantially different beam
patterns. This poses a problem for evaluation.

Basically, I decided to adjust the angle of each light to
(subjectively) place its brightest spot just in front of the water
bottle that was placed at a distance 26 ft.

In actual use, I employ more than one of these lights. One
positioned one to illuminate strongest at around 24 ft and another
one much further down the road (basically at infinity).

The Bottom Line

For commute use, I have settled on the DiNotte 5W. It is a fairly wide
beam, which has considerable nearfield advantages with respect to
signage and shoulder debris illumination. The other lights tested here
are useless for detecting peripheral objects outside their narrow cone
of illumination. Yes, I can notice and read peripheral street
signs. At 20 mph with the Cateye EL500, I never noticed those things
before.

For brevet use, there is a two light minimum for this category of
lighting. I've used two Cateye Micros (one nearfield and one for
distance). A helmet light is really also necessary for street signage
illumination. The DiNotte 5W can improve on this as long as it is
supplemented by an instant-on light that can serve to illuminate deep
into a descent. However, I am not yet sure how long the DiNotte 5W
will last on a set of AA lithiums.